Identification and characterization of phage PS166 lysogens from non-O1, O139 strains of Vibrio cholerae

摘要

Background In recent years, non-O1, O139 serogroups of Vibrio cholerae have become a major source of pathogenic infection. However, the origin and acquisition of their virulence properties remain under explored. In this regard bacteriophages of Vibrio cholerae are well known to be the carriers of pathogenic traits across various strains. So, any possible association of vibriophages and non-O1, O139 serogroups would provide a deeper insight of their pathogenic threats. Material and Method Ten non-O1, O139 clinical isolates of Vibrio cholerae were induced by mitomycin C. Virulence profiles of those isolates were determined by multiplex PCR. BglII, KpnI and HaeII were used to generate the restriction profile of isolated bacteriophage. Two of the phage harboring strains was ribotyped by Southern hybridization. Results In the present study, ten non-O1, O139 diarrheal isolates of Vibrio cholerae were examined for their ability to produce infectious phage particles out of which two strains, PG128 and PG130 were found to be positive. The host range and restriction profile of phage particles were identical to a biotype converting temperate vibriophage PS166. Both PG128 and PG130 carried unique ribotype pattern and lacked the major virulence determinants. But PG128 was found to carry hlyA, mshA, rtxC and toxR, a set of accessory virulence determinants. Conclusions The evidences present here provide definite clues for a possible phage mediated emergence of newer Vibrio choleare pathogens.